1. Field of the Invention
The present invention relates to a hemostatic unit for measuring arteriovenous bloodstreams, which is adapted to apply hemostatic treatment to the region to be measured, when arteriovenous bloodstreams are determined for clinical diagnoses, etc. by plethysmography.
2. Prior Art
Referring to the measurement of arteriovenous bloodstreams by plethysmography, a measuring strain gauge 42 is wound around the lower limb with a cuff 43 being wound around the thigh, as illustrated in FIG. 4 by way of example. An amount of compressed air is supplied to the cuff 43 to expand it for hemostatic purposes, and that state is kept for a certain period of time. Then, the internal pressure of the cuff 43 is reduced by spontaneous evacuation to electrically determine the arteriovenous bloodstreams by means of the strain gauge 42.
With such a conventional unit, however, it is impossible to obtain any rapid pressure drop required for plethysmometry and, hence, difficult to achieve any accurate determination, since the internal pressure of the cuff is reduced by spontaneous evacuation. Even when an assistant then attempts to remove the cuff to achieve complete pressure reductions, it is impossible to obtain any uniform pressure reductions. Besides, such an attempt is timeconsuming and fails to give any value of high accuracy.